SQL injection attack, querying the database type and version on Oracle | Web Security Academy

This lab contains an SQL injection vulnerability in the product category filter. You can use a UNION attack to retrieve the results from an injected query.

To solve the lab, display the database version string.

Note
On Oracle databases, every SELECT statement must specify a table to select FROM. If your UNION SELECT attack does not query from a table, you will still need to include the FROM keyword followed by a valid table name.

There is a built-in table on Oracle called DUAL which you can use for this purpose. For example: UNION SELECT 'abc' FROM DUAL